U.S. patent application number 11/909964 was filed with the patent office on 2008-08-21 for transmission power control method and mobile station.
This patent application is currently assigned to NTT DoCoMo, Inc.. Invention is credited to Takehiro Nakamura, Anil Umesh, Masafumi Usuda.
Application Number | 20080200200 11/909964 |
Document ID | / |
Family ID | 37053465 |
Filed Date | 2008-08-21 |
United States Patent
Application |
20080200200 |
Kind Code |
A1 |
Usuda; Masafumi ; et
al. |
August 21, 2008 |
Transmission Power Control Method And Mobile Station
Abstract
The present invention enables to reduce deterioration in the
radio network capacity on the E-DPCCH, by using the transmission
power offset as small as possible while satisfying a quality of the
E-DPCCH in a conventional mobile communication system using "EUL".
The present invention relates to a transmission power control
method for controlling a transmission power of an uplink control
channel (E-DPCCH) at a mobile station UE, including: measuring, at
a radio base station Node B, a reception quality of a control
signal received through the uplink control channel (E-DPCCH);
notifying, at the radio base station Node B, the measurement result
to a radio network controller RNC; determining, at the radio
network controller RNC, a transmission power offset of the uplink
control channel (E-DPCCH) based on the measurement result and
notifying the determined transmission power offset to the mobile
station UE; and controlling, at the mobile station UE, the
transmission power of the uplink control channel (E-DPCCH) by using
the transmission power offset.
Inventors: |
Usuda; Masafumi; (Tokyo,
JP) ; Umesh; Anil; (Kanagawa, JP) ; Nakamura;
Takehiro; (Kanagawa, JP) |
Correspondence
Address: |
MOTS LAW, PLLC
1001 PENNSYLVANIA AVE. N.W., SOUTH, SUITE 600
WASHINGTON
DC
20004
US
|
Assignee: |
NTT DoCoMo, Inc.
Tokyo
JP
|
Family ID: |
37053465 |
Appl. No.: |
11/909964 |
Filed: |
March 29, 2006 |
PCT Filed: |
March 29, 2006 |
PCT NO: |
PCT/JP2006/306540 |
371 Date: |
January 18, 2008 |
Current U.S.
Class: |
455/522 |
Current CPC
Class: |
H04W 52/36 20130101;
H04W 52/325 20130101 |
Class at
Publication: |
455/522 |
International
Class: |
H04B 7/00 20060101
H04B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2005 |
JP |
P2005-127064 |
Claims
1. A transmission power control method for controlling a
transmission power of an uplink control channel at a mobile
station, comprising: measuring, at a radio base station, a
reception quality of a control signal received through the uplink
control channel; notifying, at the radio base station, the
measurement result to a radio network controller; determining, at
the radio network controller, a transmission power offset of the
uplink control channel based on the measurement result, and
notifying the determined transmission power offset to the mobile
station; and controlling, at the mobile station, the transmission
power of the uplink control channel by using the transmission power
offset.
2. A transmission power control method for controlling a
transmission power of an uplink control channel at a mobile
station, comprising; determining a transmission period of an outer
loop transmission power control signal, and notifying the
determined transmission period to the mobile station; transmitting,
at the mobile station, the outer loop transmission power control
signal in the determined transmission period through an uplink user
data channel, even when uplink user data to be transmitted through
the uplink user data channel does not exist; measuring, at a radio
base station, a reception quality of the outer loop transmission
power control signal received through the uplink user data channel;
notifying, at the radio base station, the measurement result to a
radio network controller; determining, at the radio network
controller, a transmission power offset of the uplink control
channel based on the measurement result, and notifying the
determined transmission power offset to the mobile station; and
controlling, at the mobile station, the transmission power of the
uplink control channel by using the transmission power offset.
3. The transmission power control method according to claim 2,
wherein the radio network controller determines the transmission
period and notifies the determined transmission period to the
mobile station.
4. The transmission power control method according to claim 2,
wherein the radio network controller determines the transmission
period when the mobile station sets a call or when the mobile
station starts a soft handover, and notifies the determined
transmission period to the mobile station.
5. The transmission power control method according to claim 2,
wherein the transmission period is determined in accordance with a
status of the mobile station or a congestion degree of a radio
network.
6. A mobile station which transmits an uplink control channel,
comprising: an outer loop transmission power control signal
transmitter configured to transmit an outer loop transmission power
control signal through an uplink user data channel in a
predetermined transmission period, even when uplink user data to be
transmitted through the uplink user data channel does not exist;
and a transmission power controller configured to control a
transmission power of the uplink control channel by using a
transmission power offset determined by using the outer loop
transmission power control signal.
7. The mobile station according to claim 6, wherein a radio network
controller determines the predetermine transmission period and
notifies the determined transmission period.
8. The mobile station according to claim 6, wherein the
predetermined transmission period is notified when the mobile
station sets a call or when the mobile station starts a soft
handover.
9. A radio network controller used in a transmission power control
method for controlling a transmission power of an uplink control
channel at a mobile station, comprising: a transmission power
offset determining section configured to determine a transmission
power offset of the uplink control channel based on a measurement
result of a reception quality of a control signal received through
the uplink control channel, the measurement result notified from a
radio base station, and to notify the determined transmission power
offset to the mobile station.
10. A radio network controller used in a transmission power control
method for controlling a transmission power of an uplink control
channel at a mobile station, comprising; a transmission period
determining section configured to determine a transmission period
of an outer loop transmission power control signal, and to notify
the determined transmission period to the mobile station; and a
transmission power offset determining section configured to
determine a transmission power offset of the uplink control channel
based on a measurement result of a reception quality of the outer
loop transmission power control signal received through an uplink
user data channel, the measurement result notified from a radio
base station, and to notify the determined transmission power
offset to the mobile station.
11. The radio network controller according to claim 10, wherein the
transmission period determining section is configured to determine
the transmission period when the mobile station sets a call or when
the mobile station starts a soft handover, and to notify the
determined transmission period to the mobile station.
12. The radio network controller according to claim 8, wherein the
transmission period determining section is configured to determine
the transmission period in accordance with a status of the mobile
station or a congestion degree of a radio network, and to notify
the determined transmission period to the mobile station.
Description
TECHNICAL FIELD
[0001] The present invention relates to a transmission power
control method and a mobile station for controlling a transmission
power of an uplink control channel at the mobile station.
BACKGROUND ART
[0002] In a conventional mobile communication system, in an uplink
from a mobile station UE to a radio base station Node B, a radio
network controller RNC is configured to determine a transmission
rate of a dedicated channel, in consideration of radio resources of
the radio base station Node B, an interference volume in an uplink,
a transmission power of the mobile station UE, transmission
processing performance of the mobile station UE, a transmission
rate required for an upper application, and the like, and to notify
the determined transmission rate of the dedicated channel by a
message in a layer-3 (Radio Resource Control Layer) to both of the
mobile station UE and the radio base station Node B.
[0003] Here, the radio network controller RNC is provided at an
upper level of the radio base station Node B, and is an apparatus
configured to control the radio base station Node B and the mobile
station UE.
[0004] In general, data communications often cause burst traffic
compared with voice communications or TV communications. Therefore,
it is preferable that a transmission rate of a channel used for the
data communications is changed fast.
[0005] However, as shown in FIG. 10, the radio network controller
RNC integrally controls a plurality of radio base stations Node B
in general. Therefore, in the conventional mobile communication
system, there has been a problem that it is difficult to perform
fast control for changing of the transmission rate of the channel
(for example, per approximately 1 through 100 ms), due to
processing load, processing delay, or the like.
[0006] In addition, in the conventional mobile communication
system, there has also been a problem that costs for implementing
an apparatus and for operating a network are substantially
increased even if the fast control for changing of the transmission
rate of the channel can be performed.
[0007] Therefore, in the conventional mobile communication system,
control for changing of the transmission rate of the channel is
generally performed on the order from a few hundred ms to a few
seconds.
[0008] Accordingly, in the conventional mobile communication
system, when burst data transmission is performed as shown in FIG.
11(a), the data are transmitted by accepting low-speed, high-delay,
and low-transmission efficiency as shown in FIG. 11(b), or, as
shown in FIG. 11(c), by reserving radio resources for high-speed
communications to accept that radio bandwidth resources in an
unoccupied state and hardware resources in the radio base station
Node B are wasted.
[0009] It should be noted that both of the above-described radio
bandwidth resources and hardware resources are applied to the
vertical radio resources in FIG. 11.
[0010] Therefore, the 3rd Generation Partnership Project (3GPP) and
the 3rd Generation Partnership Project 2 (3GPP2), which are
international standardization organizations of the third generation
mobile communication system, have discussed a method for
controlling radio resources at high speed in a layer-1 and a media
access control (MAC) sub-layer (a layer-2) between the radio base
station Node B and the mobile station UE, so as to utilize the
radio resources effectively. Such discussions or discussed
functions will be hereinafter referred to as "Enhanced Uplink
(EUL)".
[0011] Radio resource control methods that have been discussed in
the "Enhanced Uplink" can be broadly categorized into three as
follows. The radio resource control methods will be briefly
described below.
[0012] First, a radio resource control method that is referred to
as "Time & Rate Control" has been discussed.
[0013] In such a radio resource control method, a radio base
station Node B determines a mobile station UE which can transmit
user data and a transmission rate of the user data per a
predetermined timing, so as to notify a mobile station ID as well
as the information relating to the transmission rate of the user
data (or a maximum allowable transmission rate of the user
data).
[0014] The mobile station UE designated by the radio base station
Node B transmits the user data at a designated timing and the
transmission rate (or within a range of the maximum allowable
transmission rate).
[0015] Second, a radio resource control method that is referred to
as "Rate Control per UE" has been discussed.
[0016] In such a radio resource control method, if there is user
data to be transmitted to the radio base station Node B, each
mobile station UE can transmit the user data. However, regarding
the maximum allowable transmission rate of the user data, the
transmission rate determined by the radio base station Node B and
notified to each mobile station UE for each transmission frame or
each of a plurality of transmission frames, is used.
[0017] Here, when the maximum allowable transmission rate is
notified, the radio base station Node B notifies the maximum
allowable transmission rate itself at the timing or a relative
value thereof (for example, an "Up command", a "Down command", and
a "Hold command").
[0018] Third, a radio resource control method that is referred to
as "Rate Control per Cell" has been discussed.
[0019] In such a radio resource control method, a radio base
station Node B notifies a transmission rate of the user data, which
is common among the mobile stations UE in communication, or
information required to calculate the transmission rate, so that
each mobile station UE determines the transmission rates of the
user data based on the received information.
[0020] Ideally, the "Time & Rate Control", and the "Rate
Control per UE" can be the best control methods for improving a
radio capacity in an uplink. However, a transmission rate of the
user data has to be granted after data volume stored in the buffers
of the mobile station UE, the transmission power in the mobile
station UE, or the like are grasped. Therefore, there has been a
problem that control load is increased by the radio base station
Node B.
[0021] In addition, in these radio resource control methods, there
has been a problem that overhead becomes larger by exchanges of
control signals.
[0022] On the other hand, in the "Rate Control per Cell", there is
an advantage in that control load by the radio base station Node B
is small since the radio base station Node B notifies information
which is common in cells, and each mobile station UE autonomously
seeks the transmission rate of the user data based on the received
information.
[0023] However, the radio base station Node B has to be configured
in such a manner that the user data in the uplink from any mobile
station UE can be received. Therefore, there has been a problem
that an apparatus size of the radio base station Node B becomes
large to effectively utilize the radio capacity of the uplink.
[0024] Accordingly, there has been proposed, for example, a scheme
(Autonomous ramping method) that the mobile station UE increases
the transmission rate of user data from a pre-notified initial
transmission rate in accordance with predetermined rules so that
excessive allocation of a radio capacity by the radio base station
Node B can be prevented, thereby preventing increase of the
apparatus size of radio base station Node B, as described in
Non-patent Document 1.
[0025] In such a scheme, a radio base station Node B determines a
maximum allowable transmission rate (or a parameter relating to the
maximum allowable transmission rate, the same shall apply
hereinafter) based on hardware resources or radio bandwidth
resources (for example, an interference volume in an uplink) in
each cell, so as to control the transmission rate of the user data
in communicating mobile stations. Detailed descriptions of a
control scheme based on hardware resources and a control scheme
based on an interference volume in an uplink will be given
below.
[0026] In the control scheme based on the hardware resources, a
radio base station Node B is configured to notify a maximum
allowable transmission rate to a mobile station UE connected to a
cell under the control thereof.
[0027] The radio base station Node B lowers the maximum allowable
transmission rate so as to avoid shortage of the hardware resources
when the transmission rate of the user data in the mobile station
UE connected to the cell under the control thereof is increased and
the hardware resources are insufficient.
[0028] On the other hand, the radio base station Node B again
increases the maximum allowable transmission rate when the space of
the hardware resources becomes larger, such as when the user data
transmission in the mobile station UE connected to the cell under
the control thereof has been completed, or the like.
[0029] In addition, in the control scheme based on the interference
volume in the uplink, a radio base station Node B is configured to
notify a maximum allowable transmission rate to a mobile station UE
connected to a cell under the control thereof.
[0030] When the transmission rate of the user data in the mobile
station UE connected to the cell under the control of the radio
base station Node B increases and a measured interference volume
(for example, a measured noise rise) in the uplink exceeds an
allowable value (for example, a maximum allowable noise rise), the
radio base station Node B lowers the maximum allowable transmission
rate so that the interference volume in the uplink can be within a
range of the allowable value (see, FIG. 12).
[0031] On the other hand, when the interference volume (for
example, the noise rise) in the uplink is within a range of the
allowable value (for example, the maximum allowable noise rise)
thereby having a space, such as when the user data transmission in
the mobile station UE connected to the cell under the control of
the radio base station Node B has been completed, or the like, the
radio base station Node B again increases the maximum allowable
transmission rate (see, FIG. 12).
[0032] Further, a transmission power control in a mobile
communication system using "EUL" will be described with reference
to FIG. 13.
[0033] A transmitter 101 in the mobile station UE is configured to
periodically transmit a Dedicated Physical Control Channel (DPCCH),
to which a layer-1 control information such as a pilot signal, a
TPC command or the like are mapped.
[0034] In addition, the transmitter 101 of the mobile station UE is
configured to transmit a Dedicated Physical Data Channel (DPDCH) or
an Enhanced Dedicated Physical Data Channel (E-DPDCH) to which the
uplink user data or the control information in more than layer 2
are mapped, in accordance with presence or absence of uplink user
data to be transmitted, or presence or absence of a transmission
opportunity allocation.
[0035] An SIR calculating section 202 of the radio base station
Node B calculates a reception signal to interference power ratio (a
reception SIR) of the received DPCH, so as to compare the set
target SIR with the reception SIR.
[0036] When the reception SIR is larger than the target SIR, a
transmitter 203 of the radio base station Node B transmits a "Down"
command to the mobile station UE. When the reception SIR is smaller
than the target SIR, the transmitter 203 of the radio base station
Node B transmits an "Up" command to the mobile station UE.
[0037] A series of operation described above is referred to as
"inner loop transmission power control".
[0038] On the other hand, an input section 301 of the radio network
controller RNC is configured to measure a reception quality of the
E-DPDCH (or the DPDCH).
[0039] Then, a controller 302 of the radio network controller RNC
is configured to set a target SIR of the radio base station Node B
based on the measurement result, and to determine a transmission
wave amplitude ratio between the E-DPDCH transmitted from the
mobile station UE and the DPCCH (the above transmission amplitude
ratio is hereinafter referred to as "gain factor"), so as to notify
the determined gain factor to the mobile station UE.
[0040] A series of operation described above is referred to as
"outer loop transmission power control".
[0041] In the conventional mobile communication system using "EUL",
"outer loop transmission power control" can be adapted to various
fluctuations in a radio environment, such as when the mobile
station UE shifts to a soft handover status, when the transmission
rate of the mobile station UE has changed, when the radio waves are
interrupted by such as buildings, or the like.
[0042] On the other hand, the transmitter 101 of the mobile station
UE is configured to transmit an E-DPCCH (uplink control channel) by
a fixed transmission power offset (a transmission power ratio
between the E-DPCCH and the DPCCH).
[0043] However, if user data to be transmitted through the E-DPDCH
does not exist, only "inner loop transmission power control" is
performed without "outer loop transmission power control". In such
a case, the gain factor or the target SIR cannot be set
appropriately in accordance with the propagation environment
changing, thereby it is not possible to transmit uplink user data
with an appropriate transmission power when the transmission is
restarted. This causes a problem of deterioration in the radio
quality.
[0044] In addition, data is transmitted by a fixed transmission
power offset on the E-DPCCH, thereby the transmission power offset
cannot be changed flexibly in accordance with the radio environment
changing. This causes problem of deterioration in the radio network
capacity.
[0045] (Non-patent Document 1) 3GPP TSG-RAN R2-042010
DISCLOSURE OF THE INVENTION
[0046] The present invention has been made considering the
above-described problems, and its object is to provide a
transmission power control method and a mobile station that makes
it possible to reduce deterioration in the radio network capacity
on the E-DPCCH, by using the transmission power oftset as small as
possible while satisfying a quality of the E-DPCCH in a
conventional mobile communication system using "EUL".
[0047] A first aspect of the present invention is summarized as a
transmission power control method for controlling a transmission
power of an uplink control channel at a mobile station, including:
measuring, at a radio base station, a reception quality of a
control signal received through the uplink control channel;
notifying, at the radio base station, the measurement result to a
radio network controller; determining, at the radio network
controller, a transmission power of set of the uplink control
channel based on the measurement result, and notifying the
determined transmission power offset to the mobile station; and
controlling, at the mobile station, the transmission power of the
uplink control channel by using the transmission power offset.
[0048] A second aspect of the present invention is summarized as a
transmission power control method for controlling a transmission
power of an uplink control channel at a mobile station, including:
determining a transmission period of an outer loop transmission
power control signal, and notifying the determined transmission
period to the mobile station; transmitting, at the mobile station,
the outer loop transmission power control signal in the determined
transmission period through an uplink user data channel, even when
uplink user data to be transmitted through the uplink user data
channel does not exist measuring, at a radio base station, a
reception quality of the outer loop transmission power control
signal received through the uplink user data channel; notifying, at
the radio base station, the measurement result to a radio network
controller; determining, at the radio network controller, a
transmission power offset of the uplink control channel based on
the measurement result, and notifying the determined transmission
power offset to the mobile station; and controlling, at the mobile
station, the transmission power of the uplink control channel by
using the transmission power offset.
[0049] In the second aspect of the present invention, the radio
network controller may determine the transmission period and notify
the determined transmission period to the mobile station.
[0050] In the second aspect of the present invention, the radio
network controller may determine the transmission period when the
mobile station sets a call or when the mobile station starts a soft
handover, and notify the determined transmission period to the
mobile station.
[0051] In the second aspect of the present invention, the
transmission period may be determined in accordance with a status
of the mobile station or a congestion degree of a radio
network.
[0052] A third aspect of the present invention is summarized as a
mobile station which transmits an uplink control channel,
including: an outer loop transmission power control signal
transmitter configured to transmit an outer loop transmission power
control signal through an uplink user data channel in a
predetermined transmission period, even when uplink user data to be
transmitted through the uplink user data channel does not exist;
and a transmission power controller configured to control a
transmission power of the uplink control channel by using a
transmission power offset determined by using the outer loop
transmission power control signal.
[0053] In the third aspect of the present invention, the radio
network controller may determine the predetermine transmission
period and notify the determined transmission period.
[0054] A fourth aspect of the present invention is summarized as a
radio network controller, including: a transmission power offset
determining section configured to determine a transmission power
offset of the uplink control channel based on a measurement result
of a reception quality of a control signal received through the
uplink control channel, the measurement result notified from a
radio base station, and to notify the determined transmission power
offset to the mobile station.
[0055] A fifth aspect of the present invention is summarized as a
radio network controller used in a transmission power control
method for controlling a transmission power of an uplink control
channel at a mobile station, including; a transmission period
determining section configured to determine a transmission period
of an outer loop transmission power control signal, and to notify
the determined transmission period to the mobile station; and a
transmission power offset determining section configured to
determine a transmission power offset of the uplink control channel
based on a measurement result of a reception quality of the outer
loop transmission power control signal received through an uplink
user data channel, the measurement result notified from a radio
base station, and to notify the determined transmission power
offset to the mobile station.
[0056] In the fifth aspect of the present invention, the
transmission period determining section may determine the
transmission period when the mobile station sets a call or when the
mobile station starts a soft handover, and notify the determined
transmission period to the mobile station.
[0057] In the fifth aspect of the present invention, the
transmission determining section may determine the transmission
period in accordance with a status of the mobile station or a
congestion degree of a radio network, and notify the determined
transmission period to the mobile station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] FIG. 1 is a functional block diagram of a mobile station of
a mobile communication system according to the first embodiment of
the present invention.
[0059] FIG. 2 is a functional block diagram of a baseband signal
processing section in a mobile station of the mobile communication
system according to the first embodiment of the present
invention.
[0060] FIG. 3 is a functional block diagram of a MAC-e processing
section of the baseband signal processing section in a mobile
station of the mobile communication system according to the first
embodiment of the present invention.
[0061] FIG. 4 is a functional block diagram of a layer-1 processing
section of the baseband signal processing section in a mobile
station of the mobile communication system according to the first
embodiment of the present invention.
[0062] FIG. 5 is a functional block diagram of a radio base station
of the mobile communication system according to the first
embodiment of the present invention.
[0063] FIG. 6 is a functional block diagram of a baseband signal
processing section in a radio base station of the mobile
communication system according to the first embodiment of the
present invention.
[0064] FIG. 7 is a functional block diagram of a MAC-E and layer-1
processing section (configuration for uplink), of the baseband
signal processing section in a radio base station of the mobile
communication system according to the first embodiment of the
present invention.
[0065] FIG. 8 is a functional block diagram of a MAC-e functional
section of the MAC-E and layer-1 processing section (configuration
for uplink), of the baseband signal processing section in a radio
base station of the mobile communication system according to the
first embodiment of the present invention.
[0066] FIG. 9 is a functional block diagram of a radio network
controller of the mobile communication system according to the
first embodiment of the present invention.
[0067] FIG. 10 is a diagram showing an entire configuration of a
general mobile communication system.
[0068] FIGS. 11(a) to 11(c) are graphs illustrating operations at
the time of burst data transmission in a conventional mobile
communication system.
[0069] FIG. 12 is a diagram for explaining an operation for
controlling transmission rate in uplink in a conventional mobile
communication system.
[0070] FIG. 13 is a diagram for explaining a transmission power
control system in a conventional mobile communication system.
BEST MODE FOR CARRYING OUT THE INVENTION
(Mobile Communication System According to First Embodiment of the
Present Invention)
[0071] A description will be given of a configuration of a mobile
communication system according to a first embodiment of the present
invention with reference to FIGS. 1 to 9.
[0072] It should be noted that, as shown in FIG. 10, the mobile
communication system according to this embodiment is provided with
a plurality of radio base stations Node B #1 to Node B #5 and a
radio network controller RNC.
[0073] The mobile communication system according to the present
embodiment is configured to raise a transmission rate of user data
automatically up to the maximum allowable transmission rate. The
transmission rate of the user data is transmitted through an uplink
by a mobile station UE.
[0074] Further, the mobile communication system according to the
present embodiment may set a transmission rate of user data
transmitted from a mobile station through the uplink, as a maximum
allowable transmission rate.
[0075] In addition, in the mobile communication system according to
this embodiment, a "High Speed Downlink Packet Access (HSDPA)" is
used in a downlink, and an "Enhanced Uplink (EUL)" is used in an
uplink. It should be noted that in both of the HSDPA and the EUL,
retransmission control (N process stop and wait) shall be performed
by a "Hybrid Automatic Repeat Request (HARQ)".
[0076] Therefore, an Enhanced Dedicated Physical Channel,
configured of an Enhanced Dedicated Physical Data Channel and an
Enhanced Dedicated Physical Control Channel, and a Dedicated
Physical Channel, configured of a Dedicated Physical Data Channel
(DPDCH) and a Dedicated Physical Control Channel (DPCCH), are used
in the uplink.
[0077] Here, the E-DPCCH transmits the EUL control data such as a
transmission format number for defining a transmission format
(transmission block size, or the like) of the E-DPDCH, HARQ related
information (a number of retransmissions, or the like), and
scheduling related information (transmission power, buffer
residence-volume, or the like in the mobile station UE).
[0078] In addition, the E-DPDCH is paired with the E-DPCCH, and
transmits user data for the mobile station UE based on the EUL
control data transmitted through the E-DPCCH.
[0079] The DPCCH transmits control data such as a pilot symbol used
for RAKE combining, SIR measurement, or the like, a Transport
Format Combination Indicator (TFCI) for identifying a transmission
format of uplink DPDCH, and a transmission power control bit in a
downlink.
[0080] In addition, the DPDCH is paired with the DPCCH, and
transmits user data for the mobile station UE based on the control
data transmitted through the DPCCH. However, if user data to be
transmitted does not exist in the mobile station UE, the DPDCH can
be configured not to be transmitted.
[0081] In addition, in the uplink, a "High Speed Dedicated Physical
Control Channel (HS-DPCCH)", which is required when the HSPDA is
applied, is also used.
[0082] The HS-DPCCH transmits a Channel Quality Indicator (CQI)
measured in the downlink, and a transmission acknowledgement signal
(Ack or Nack) for the HS-DPCCH.
[0083] As shown in FIG. 1, the mobile station UE according to this
embodiment is provided with a bus interface 31, a call processing
section 32, a baseband processing section 33, a radio frequency
(RF) section 34, and a transmission--reception antenna 35.
[0084] However, these functions can be independently present as a
hardware, and can be partly or entirely integrated, or can be
configured through a process of software.
[0085] The bus interface 31 is configured to forward user data
output from the call processing section 32 to another functional
section (for example, an application related functional section).
In addition, the bus interface 31 is configured to forward user
data transmitted from another functional section (for example, the
application related functional section) to the call processing
section 32.
[0086] The call processing section 32 is configured to perform a
call control processing for transmitting and receiving user
data.
[0087] The baseband signal processing section 33 is configured to
acquire user data by performing a layer-1 processing including a
despreading processing, a RAKE combining processing, and a Forward
Error Correction (FEC) decode processing, a Media Access Control
(MAC) processing including a MAC-e processing and a MAC-d
processing, and a Radio Link Control (RLC) processing against the
baseband signals transmitted from the RF section 34, so as to
transmit the acquired user data to the call processing section
32.
[0088] In addition, the baseband signal processing section 33 is
configured to generate baseband signals by performing an RLC
processing, a MAC processing, or a layer-1 processing against the
user data transmitted from the call processing section 32 so as to
transmit the baseband signals to the RF section 34.
[0089] Detailed description of the functions of the baseband signal
processing section 33 will be given later.
[0090] The RF section 34 is configured to generate baseband signals
by performing the detection processing, the filtering processing,
the quantization processing, or the like against radio frequency
signals received through the transmission--reception antenna 35, so
as to transmit the generated baseband signals to the baseband
signal processing section 33.
[0091] In addition, the RF section 34 is configured to convert the
baseband signals transmitted from the baseband signal processing
section 33 to the radio frequency signals.
[0092] As shown in FIG. 2, the baseband signal processing section
33 is provided with an RLC processing section 33a, a MAC-d
processing section 33b, a MAC-e processing section 33c, and a
layer-1 processing section 33d.
[0093] The RLC processing section 33a is configured to perform a
processing (RLC processing) of an upper layer of a layer-2 against
user data transmitted from the call processing section 32 so as to
transmit the user data to the MAC-d processing section 33b.
[0094] The MACH processing section 33b is configured to grant a
channel identifier header based on a logical channel to which data
is originated, so as to generate a transmission format in the
uplink.
[0095] As shown in FIG. 3, the MAC-e processing section 33c is
provided with an Enhanced Transport Format Combination (E-TFC)
selecting section 33c1 and an HARQ processing section 33c2.
[0096] The E-TFC selecting section 33c1 is configured to determine
a transmission format (E-TFC) of the E-DPDCH based on scheduling
signals transmitted from the radio base station Node B.
[0097] In addition, the E-TFC selecting section 33c1 is configured
to transmit transmission format information on the determined
transmission format (a transmission data block size, a transmission
power ratio between the E-DPDCH and the DPCCH, or the like) to the
layer-1 processing section 33d, and to transmit the determined
transmission format information to the HARQ processing section
33c2.
[0098] Here, the scheduling signals include such as an absolute
value of the maximum allowable transmission rate of the user data
at the mobile station UE, which is transmitted through an Absolute
Grant Control Channel (AGCH) (for example, a maximum allowable
transmission data block size, a maximum value of a transmission
power ratio between the E-DPDCH and the DPCCH (maximum allowable
transmission power ratio), or the like).
[0099] In this description, unless specified otherwise, it is
assumed that the maximum allowable transmission rate includes a
parameter related to the maximum allowable transmission rate.
[0100] Such scheduling signals are information notified in the cell
where the mobile station UE is located, and include control
information for all the mobile stations located in the cell, or a
specific group of the mobile stations located in the cell.
[0101] The HARQ processing section 33c2 is configured to perform
process control for the "stop-and-wait of N-process", so as to
transmit the user data in the uplink, based on a transmission
acknowledgement signal (Ack/Nack for uplink data) transmitted from
the radio base station Node B.
[0102] Specifically, the HARQ processing section 33c2 is configured
to determine, based on the transmission acknowledgement signals
(Ack/Nack for the uplink) transmitted from the radio base station
Node B, whether or not the reception processing of the uplink user
data at the radio base station Node B has been successful.
[0103] When the transmission acknowledgement signal transmitted
from the radio base station Node B to the HARQ processing is an
"Ack" (reception processing of the uplink user data has been
successful), the HARQ processing section 33c2 transmits new uplink
user data at the HARQ processing.
[0104] Further, when the transmission acknowledgement signal
transmitted from the radio base station Node B to the HARQ
processing is a "NACK" (reception processing of the uplink user
data has not been successful), the HARQ processing section 33c2
retransmits the uplink user data at the HARQ processing.
[0105] In addition, when the HARQ processing section 33c2 has not
transmitted uplink user data for a predetermined period, the HARQ
processing section 33c2 is configured to transmit transmission data
blocks including outer loop transmission power control signals (MAC
layer control information) in accordance with a transmission period
notified from the radio network controller RNC (the predetermined
transmission period), even when uplink user data to be transmitted
does not exist.
[0106] It is assumed that the outer loop transmission power control
signals include such as a status of the mobile station UE (for
example, availability of the transmission power, a status of
transmission buffer, or the like) or a CRC bit, or the like.
Further, padding processing is performed against the transmission
data blocks including the outer loop transmission power control
signals, until the transmission data block reaches its minimum
size.
[0107] The above-described transmission period is notified from the
radio network controller RNC by such as an RRC message or the like,
when the mobile station US sets a call or when the mobile station
UE starts a soft handover.
[0108] As shown in FIG. 4, the layer-1 processing section 33d
includes a control information receiver 33d1, a gain factor
correspondence table storing section 33d2, a user data transmitter
33d3, and a control signal transmitter 33d4.
[0109] The control information receiver 33d1 is configured to
receive control information relating the layer-1 and the layer-2,
from the radio network controller RNC through the call processing
section 33d1.
[0110] The gain factor correspondence table storing section 33d2 is
configured to extract, from the layer-2 related control information
received at the control information receiver 33d1, a correspondence
table showing correspondence between a transmission data block size
of uplink user data and an EDCH transmission power ratio relating
to the uplink user data, so as to store the extracted
correspondence table.
[0111] The user data transmitter 33d8 is configured to transmit the
uplink user data in accordance with the transmission power ratio
(transmission rate) determined by using the correspondence table,
which indicates correspondence between the transmission data block
size and the EDCH transmission power ratio, and is stored in the
gain factor correspondence table storing section 33d2.
[0112] In addition, the user data transmitter 33d8 is configured to
transmit the transmission data blocks including outer loop
transmission power control signals (MAC layer control information)
by using the above transmission power ratio.
[0113] The control signal transmitter 33d4 is configured to control
the transmission power of the E-DPCCH (uplink control channel) by
using the transmission power offset determined and notified by the
radio network controller RNC, and to transmit the E-DPCCH.
[0114] As shown in FIG. 5, the radio base station Node B according
to this embodiment is provided with an HWY interface 11, a baseband
signal processing section 12, a call control section 13, at least
one transmitter-receiver section 14, at least one amplifier section
15, and at least one transmission--reception antenna 16.
[0115] The HWY interface 11 is an interface with a radio network
controller RNC. Specifically, the HWY interface 11 is configured to
receive user data transmitted from the radio network controller RNC
to a mobile station UE through a downlink, so as to enter the user
data to the baseband signal processing section 12. In addition, the
HWY interface 11 is configured to receive control data for the
radio base station Node B from the radio network controller RNC, so
as to enter the received control data to the call control section
13.
[0116] In addition, the HWY interface 11 is configured to acquire,
from the baseband signal processing section 12, user data included
in the uplink signals which are received from a mobile station UE
through an uplink, so as to transmit the acquired user data to the
radio network controller RNC. Further, the HWY interface 11 is
configured to acquire control data for the radio network controller
RNC from the call control section 13, so as to transmit the
acquired control data to the radio network controller RNC.
[0117] The baseband signal processing section 12 is configured to
generate baseband signals by performing the MAC-e processing and
the layer-1 processing against the user data acquired from the HWY
interface 11, so as to forward the generated baseband signals to
the transmitter-receiver section 14.
[0118] Here, the MAC processing in the downlink includes an HARQ
processing, a scheduling processing, a transmission rate control
processing, or the like. In addition, the layer-1 processing in the
downlink includes a channel coding processing of user data, a
spreading processing, or the like.
[0119] In addition, the baseband signal processing section 12 is
configured to extract user data by performing the layer-1
processing and the MAC-e processing against the baseband signals
acquired from the transmitter-receiver section 14, so as to forward
the extracted user data to the HWY interface 11.
[0120] Here, the MAC-e processing in the uplink includes an HARQ
processing, a scheduling processing, a transmission rate control
processing, a header disposal processing, or the like. In addition,
the layer-1 processing in the uplink includes a despreading
processing, a RAKE combining processing, an error correction decode
processing, or the like.
[0121] Detailed description of the functions of the baseband signal
processing section 12 will be given later. In addition, the call
control section 13 is configured to perform the call control
processing based on the control data acquired from the HWY
interface 11.
[0122] The transmitter-receiver section 14 is configured to perform
processing of converting baseband signals acquired from the
baseband signal processing section 12, into radio frequency signals
(downlink signals), so as to transmit the converted radio frequency
signals to the amplifier section 15. In addition, the
transmitter-receiver 14 is configured to perform processing of
converting the radio frequency signals (uplink signals) acquired
from the amplifier section 15, into the baseband signals, so as to
transmit the converted baseband signals to the baseband signal
processing section 12.
[0123] The amplifier section 15 is configured to amplify the
downlink signals acquired from the transmitter-receiver section 14,
so as to transmit the amplified downlink signals to the mobile
station UE through the transmission--reception antenna 16. In
addition, the amplifier 15 is configured to amplify the uplink
signals received by the transmission--reception antenna 16, so as
to transmit the amplified uplink signals to the
transmitter-receiver section 14.
[0124] As shown in FIG. 6, the baseband signal processing section
12 is provided with a MAC-e and layer-1 processing section 123.
[0125] The MAC-e and layer-1 processing section 123 is configured
to perform, against the baseband signals acquired from the
transmitter-receiver section 14, a despreading processing, a RAKE
combining processing, an error correction decode processing, an
HARQ processing, or the like.
[0126] The MAC-d processing section 122 is configured to perform
such as a header discard processing or the like, against output
signals from the MAC-e and layer-1 processing section 123.
[0127] The RLC processing section 121 is configured to perform such
as a retransmission control processing in the RLC layer, a
reconstruction processing in an RLC-SDU or the like, against the
output signals from the MAC-d processing section 122.
[0128] However, these functions are not clearly divided per
hardware, and can be acquired by software.
[0129] As shown in FIG. 7, the MAC-e and layer-1 processing section
(configuration for the uplink) 123 is provided with a DPCCH RAKE
section 123a, a DPDCH RAKE section 123b, an E-DPCCH RAKE section
123c, an E-DPDCH RAKE section 123d, an HS-DPCCH RAKE section 123e,
a Transport Format Combination Indicator (TFCI) decoder section
123g, buffers 123h and 123m, re-despreading sections 123i and 123n,
FEC decoder sections 123j and 123p, an E-DPCCH decoder section
123k, a MAC-e functional section 123l, an HARQ buffer 123o, a
MAC-hs functional section 123q, an SIR measurement section 123s,
and an SIR comparison section 123t.
[0130] The E-DPCCH RAKE section 123c is configured to perform,
against the E-DPCCH in the baseband signals transmitted from the
transmitter-receiver section 14, the despreading processing and the
RAKE combining processing using a pilot symbol included in the
DPCCH.
[0131] The E-DPCCH decoder section 123k is configured to acquire
transmission format number related information, HARQ related
information, scheduling related information, or the like, by
performing the decode processing against the RAKE combining outputs
of the E-DPCCH RAKE section 123c, so as to enter the acquired
information to the MAC-e functional section 123l.
[0132] The E-DPDCH RAKE section 123d is configured to perform,
against the E-DPDCH in the baseband signals transmitted from the
transmitter-receiver section 14, a despreading processing using the
transmission format information (the number of codes) transmitted
from the MAC-e functional section 123l and the RAKE combining
processing using the pilot symbol included in the DPCCH.
[0133] The buffer 123m is configured to store the RAKE combining
outputs of the E-DPDCH RAKE section 123d based on the transmission
format information (the number of symbols) transmitted from the
MAC-e functional section 123l.
[0134] The re-despreading section 123n is configured to perform a
despreading processing against the RAKE combining outputs of the
E-DPDCH RAKE section 123d stored in the buffer 123m, based on the
transmission format information (a spreading factor) transmitted
from the MAC-E functional section 123l.
[0135] The HARQ buffer 123o is configured to store the despreading
processing outputs of the redespreading section 123n, based on the
transmission format information transmitted from the MAC-e
functional section 123l.
[0136] The FEC decoder section 123p is configured to perform an
error correction decoding processing (the FEC decoding processing)
against the despreading processing outputs of the re-despreading
section 123n, which is stored in the HARQ buffer 123o, based on the
transmission format information (transmission data block size)
transmitted from the MAC-e functional section 123l.
[0137] The MAC-e functional section 123l is configured to calculate
and output the transmission format information (the number of
codes, the number of symbols, the spreading factor, the
transmission data block size, and the like) based on the
transmission format number related information, the HARQ related
information, the scheduling related information, and the like,
which are acquired from the E-DPCCH decoder section 123k.
[0138] The SIR measurement section 123s is configured to measure a
reception SIR by using the pilot portion included in the DPCCH.
[0139] The SIR comparison section 123t is configured to compare a
target SIR notified from the radio network controller RNC through
the HWY interface 11, with the measured reception SIR. Then, based
on the comparison result, the SIR comparison section 123t instructs
the downlink configuration of the baseband signal processing
section 12 to transmit a "Down" command or an "Up" command through
the downlink.
[0140] In addition, as shown in FIG. 8, the MACE functional section
123l is provided with a receive processing command section 123l1,
an HARQ control section 123l2, and a scheduling section 123l3.
[0141] The receive processing command section 123l1 is configured
to transmit the transmission format number related information, the
HARQ related information, and the scheduling related information,
which are entered from the E-DPCCH decoder section 123k, to the
HARQ control section 123l2.
[0142] In addition, the receive processing command section 123l1 is
configured to transmit, to the scheduling section 123l3, the
scheduling related information entered from the E-DPCCH decoder
123k.
[0143] Further, the receive processing command section 123l1 is
configured to output the transmission format information
corresponding to the transmission format number entered from the
E-DPCCH decoder section 123k.
[0144] The HARQ control section 123l2 is configured to determine
whether or not the receive processing of uplink user data has been
successful, based on the CRC result entered from the FEC decoder
section 123p.
[0145] Then, the HARQ control section 123l2 is configured to
generate a transmission acknowledgement signal (Ack or Nack), based
on the determination result, so as to transmit the generated
transmission acknowledgement signals to the configuration for the
downlink of the baseband signal processing section 12.
[0146] In addition, the HARQ control section 123l2 is configured to
transmit the uplink user data entered from the FEC decoder section
123p to the radio network controller RNC, when the above
determination result has been "OK".
[0147] In addition, the HARQ control section 123l2 is configured to
clear soft decision information stored in the HARQ buffer 123o when
the above determination result is "OK".
[0148] On the other hand, when the above determination result is
"NG", the HARQ control section 123l2 is configured to store the
uplink user data in the HARQ buffer 123o, the uplink user data.
[0149] In addition, the HARQ control section 123l2 is configured to
forward the above determination result to the receive processing
command section 123l1.
[0150] The receive processing control command section 123l1 is
configured to notify the E-DPDCH RAKE section 123d and the buffer
123m of an hardware resource to be prepared for the following
transmission time interval (TTI), so as to perform notification for
reserving the resource in the HARQ buffer 123o.
[0151] In addition, when the uplink user data is stored in the
buffer 123m, the receive processing command section 123l1 is
configured to instruct the HARQ buffer 123o and the FEC decoder
section 123p to perform the FEC decoding processing after adding
the uplink user data, which is stored in the HARQ buffer 123o, in a
process corresponding to the TTI and a newly received uplink user
data, per TTI.
[0152] In addition, the scheduling section 123l3 is configured to
instruct the configuration for the downlink of the baseband signal
processing section 12 to notify the scheduling signals including
the maximum allowable transmission rate (maximum allowable
transmission data block size, maximum allowable transmission power
ratio, or the like), based on radio resources in the uplink of the
radio base station Node B, interference volume (noise rise) in the
uplink, or the like.
[0153] To be more specific, the scheduling section 123l3 is
configured to determine the maximum allowable transmission rate
based on scheduling related information (radio resource in the
uplink) transmitted from the E-DPCCH decoder section 123k so as to
control the transmission rate of user data of the mobile station in
communication.
[0154] Detailed descriptions of a control method based on the
hardware resources and a control method based on the interference
volume in the uplink will be given below.
[0155] In the control method based on the hardware resources, the
scheduling section 123l3 is configured to notify the maximum
allowable transmission rate through the AGCH to the mobile station
UE connected to a cell under the control of the radio base station
Node B.
[0156] When the transmission rate of user data in the mobile
station UE connected to the cell under the control of the radio
base station Node B increases and the hardware resources becomes
insufficient, the scheduling section 123l3 lowers the maximum
allowable transmission rate so that shortage of the hardware
resources will not be caused.
[0157] On the other hand, when the hardware resources have spaces
in such a case when the user data transmission in the mobile
station UE connected to the cell under the control of the radio
base station Node B is completed, or the like, the scheduling
section 123l3 again increases the maximum allowable transmission
rate.
[0158] In addition, in the control method based on the interference
volume in the uplink, the scheduling section 123l3 is configured to
notify the maximum allowable transmission rate through the AGCH to
the mobile station UE connected to the cell under the control of
the radio base station Node B.
[0159] When the transmission rate of user data in the mobile
station UE connected to the cell under the control of the radio
base station Node B increases and the interference volume (for
example, the noise rise) in the uplink exceeds an allowable value
(for example, the maximum allowable noise rise), the scheduling
section 123l3 lowers the maximum allowable transmission rate so
that the interference volume in the uplink can fall within a range
of the allowable value (see, FIG. 12).
[0160] On the other hand, when the interference volume (for
example, the noise rise) in the uplink falls within the range of
the allowable value (for example, the maximum allowable noise rise)
and there is a space therein in the case when the user data
transmission in the mobile station UE connected to the cell under
the control of the radio base station Node B is completed, or the
like, the scheduling section 123l3 again increases the maximum
allowable transmission rate (see, FIG. 12).
[0161] The scheduling section 123l3 is configured to determine
priority class for each logical channel used for transmitting
uplink user data at the mobile station UE. Then, the scheduling
section 123l3 determines an absolute value of maximum allowable
transmission rate of uplink user data for each priority class, so
as to transmit scheduling signals to the downlink configuration of
the baseband signal processing section 12. The scheduling signals
include the absolute value of maximum allowable transmission rate
for each priority class, and a priority class ID for identifying
the priority class.
[0162] The radio network controller RNC according to the present
embodiment is an apparatus located on upper level of the radio base
station Node B and configured to control radio communication
between the radio base station Node B and the mobile station
UE.
[0163] As shown in FIG. 9, the radio network controller RNC
according to this embodiment is provided with an exchange interface
51, a Radio Link Control (RLC) layer processing section 52, a MAC
layer processing section 53, a media signal processing section 54,
a radio base station interface 55, a call control section 56, and
an outer loop transmission power controller 57.
[0164] The exchange interface 51 is an interface with an exchange
1. The exchange interface 51 is configured to forward the downlink
signals transmitted from the exchange 1 to the RLC layer processing
section 52, and to forward the uplink signals transmitted from the
RLC layer processing section 52 to the exchange 1.
[0165] The RLC layer processing section 52 is configured to perform
an RLC (Radio Link Control) sub-layer processing such as a
synthesis processing of a header (e.g. a sequence number), a
trailer, or the like.
[0166] The RLC layer processing section 52 is also configured to
transmit the uplink signals to the exchange interface 51 and to
transmit the downlink signals to the MAC layer processing section
53, after the RLC sub-layer processing is performed.
[0167] The MAC layer processing section 53 is configured to perform
a MAC layer processing such as a priority control processing or a
header granting processing.
[0168] The MAC layer processing section 53 is also configured to
transmit the uplink signals to the RLC layer processing section 52
and to transmit the downlink signals to the radio base station
interface 55 (or a media signal processing section 54), after the
MAC layer processing is performed.
[0169] The media signal processing section 54 is configured to
perform a media signal processing against voice signals or real
time image signals.
[0170] The media signal processing section 54 is also configured to
transmit the uplink signals to the MAC layer processing section 53
and to transmit the downlink signals to the radio base station
interface 55, after the media signal processing is performed.
[0171] The radio base station interface 55 is an interface with the
radio base station Node B. The radio base station interface 55 is
configured to forward the uplink signals transmitted from the radio
base station Node B to the MAC layer processing section 53 (or the
media signal processing section 54) and to forward the downlink
signals transmitted from the MAC layer processing section 53 (or
the media signal processing section 54) to the radio base station
Node B.
[0172] The call control section 56 is configured to perform a radio
resource control processing, a channel setup and open processing by
the layer-3 signaling, or the like. Here, the radio resource
control processing includes a call admission control processing, a
handover processing, or the like.
[0173] The outer loop transmission power controller 57 is
configured to determine transmission period of the outer loop
transmission power control signals so as to notify the determined
transmission period to the mobile station UE.
[0174] For example, the outer loop transmission power controller 57
is configured to determine transmission period of the outer loop
transmission power control signal based on status of the mobile
station UE (whether or not the mobile station UE is in soft
handover status, or the like) or congestion degree in the uplink
(radio network), and to notify the determined transmission period
to the mobile station UE.
[0175] Further, the outer loop transmission power controller 57 may
determine the above-described transmission period when the mobile
station UE sets a call (E-DCH) or when the mobile station UE starts
a soft handover, and notify the determined transmission period to
the mobile station UE.
[0176] The outer loop transmission power controller 57 may
determine a transmission power offset (a transmission power ratio
between the E-DPDCH and the DPCCH, or a gain factor) of the E-DPDCH
(uplink control channel) based on the measurement result of the
reception quality of the outer loop transmission power control
signal (for example, the reception SIR) received through the
E-DPDCH (uplink user data channel) notified from the radio base
station Node B, so as to notify the determined transmission power
offset to the mobile station UE.
[0177] Alternatively, the outer loop transmission power controller
57 may determine the transmission power offset (the transmission
power ratio between the E-DPDCH and the DPCCH, or the gain factor)
of the E-DPCCH (uplink control channel) based on the measurement
result of the reception quality of the control signal (for example,
the reception SIR) received through the E-DPCCH (uplink control
channel) notified from the radio base station Node B, so as to
notify the determined transmission power offset to the mobile
station UE.
[0178] In addition, the outer loop transmission power controller 57
is configured to determine a target reception quality of the uplink
user data channel (target SIR) based on the above-described
measurement result, and to notify the determined result to the
radio base station Node B.
[0179] For example, the outer loop transmission power controller 57
determines the target SIR or the gain factor based on the uplink
user data received from the radio base station Node B, the CRC
result, the number of retransmissions, or the like.
[0180] In other words, when the CRC result is "NG" and the number
of retransmissions is large, the outer loop transmission power
controller 57 either instructs the radio base station Node B to set
the target SIR high, or instructs the radio base station Node B and
the mobile station UE to set the gain factor high.
[0181] In addition, the outer loop transmission power controller 57
may use an RRC message so as to notify the above-described
transmission period, target SIR, and transmission power offset, to
the mobile station UE or to the radio base station Node B.
MODIFIED EXAMPLE 1
[0182] The present invention is not limited to the above
embodiment, and various modifications can be applied to the present
invention.
[0183] According to the mobile communication system of the modified
example 1, the above-described "function of determining
transmission period of the outer loop transmission power control
signals and notifying the determined transmission period to the
mobile station (transmission period determining section)" is
performed at such as Operation & Maintenance Terminal (OMT)
connected to the radio base station Node B, an upper node, or the
like, instead of the radio network controller RNC.
[0184] Further, according to the mobile communication system of the
modified example 1, the above-described "function of determining
the transmission power offset (the transmission power ratio between
the E-DPDCH and the DPCCH, or the gain factor) of the E-DPDCH
(uplink user data channel) based on the measurement result of the
reception quality of the outer loop transmission power control
signal (reception SIR) received through the E-DPDCH (uplink user
data channel) notified from the radio base station Node B, and of
notifying the determined transmission power offset to the mobile
station UE (transmission power offset determining section)" is also
performed at such as the above-described OMT, the upper node, or
the like.
[0185] Further, according to the mobile communication system of the
modified example 1, the above-described "function of determining
the transmission power offset (the transmission power ratio between
the E-DPDCH and the DPCCH, or the gain factor) of the E-DPDCH
(uplink control channel) based on the measurement result of the
reception quality of the control signal (reception SIR) received
through the E-DOCCH (uplink control channel) notified from the
radio base station Node B, and of notifying the determined
transmission power offset to the mobile station UE (transmission
power offset determining section)" is also performed at such as the
above-described OMT, the upper node, or the like.
[0186] In addition, the mobile communication system according to
the modified example 1, the above-described "function of
determining a target reception quality of the uplink user data
channel based on the measurement result (target reception quality
determining section)" is performed at the above-described OMT, the
upper node, or the like.
[0187] Although the present invention has been described in detail
above with the embodiment, it is apparent to those skilled in the
art that the present invention is not limited to the embodiment
described in the present application. The present invention can be
implemented as altered and modified embodiments without departing
from the spirit and scope of the present invention as defined by
the description of claims. Therefore, the description of the
present application is for illustrative purposes and is not
intended to limit the present invention in any way.
INDUSTRIAL APPLICABILITY
[0188] As described above, the present invention can provide a
transmission power control method and a mobile station that makes
it possible to reduce deterioration in the radio network capacity
on the E-DPCCH, by using the transmission power offset as small as
possible while satisfying a quality of the E-DPCCH.
* * * * *